static void Update(byte *bytes, uint len,
QWords128 *keyStreamBuf, ref uint keystreamBufferPos, ref QWords128 counter, Keys128128 keys)
{
while (len > 0)
{
var remainningKeystream = KeystreamBufferSize - keystreamBufferPos;
if (remainningKeystream == 0)
{
keystreamBufferPos = 0;
remainningKeystream = KeystreamBufferSize;
var ksb = keyStreamBuf;
for (uint i = 0; i < KsBlockCount; i += 4)
{
for (uint j = 0; j < 4; j++)
{
ksb[i + j] = counter;
if (++counter.v1 == 0)
{
++counter.v0;
}
}
Cipher.encrypt_128_128_4blocks(keys, &ksb[i]);
}
}
var count = len < remainningKeystream ? len : remainningKeystream;
NaiveUtils.XorBytesUnsafe((byte *)keyStreamBuf + keystreamBufferPos, bytes, count);
bytes += count;
len -= count;
keystreamBufferPos += count;
}
}
public static void encrypt_128_128_4blocks(Keys128128 keySchedules, QWords128 *plaintext)
{
var keys = keySchedules.keys;
uint64 v01 = plaintext[0].v1, v00 = plaintext[0].v0;
uint64 v11 = plaintext[1].v1, v10 = plaintext[1].v0;
uint64 v21 = plaintext[2].v1, v20 = plaintext[2].v0;
uint64 v31 = plaintext[3].v1, v30 = plaintext[3].v0;
foreach (var key in keys)
{
const int WORDSIZE = 64;
v01 = (v01 >> 8) | (v01 << (WORDSIZE - 8)); // x = ROTR(x, 8)
v01 += v00;
v01 ^= key;
v00 = (v00 << 3) | (v00 >> (WORDSIZE - 3)); // y = ROTL(y, 3)
v00 ^= v01;
v11 = (v11 >> 8) | (v11 << (WORDSIZE - 8));
v11 += v10;
v11 ^= key;
v10 = (v10 << 3) | (v10 >> (WORDSIZE - 3));
v10 ^= v11;
v21 = (v21 >> 8) | (v21 << (WORDSIZE - 8));
v21 += v20;
v21 ^= key;
v20 = (v20 << 3) | (v20 >> (WORDSIZE - 3));
v20 ^= v21;
v31 = (v31 >> 8) | (v31 << (WORDSIZE - 8));
v31 += v30;
v31 ^= key;
v30 = (v30 << 3) | (v30 >> (WORDSIZE - 3));
v30 ^= v31;
}
plaintext[0].v1 = v01; plaintext[0].v0 = v00;
plaintext[1].v1 = v11; plaintext[1].v0 = v10;
plaintext[2].v1 = v21; plaintext[2].v0 = v20;
plaintext[3].v1 = v31; plaintext[3].v0 = v30;
}